Negative-Magnetoresistance Effects inTi2O3

Negative-magnetoresistance phenomena are reported at 4.2°K for single-crystal ${\mathrm{Ti}}_2$ ${\mathrm{O}}_3$ doped with vanadium in the 0.3-4 at.% range. The results were analyzed by time-dependent perturbation theory in terms of an inelastic scattering mechanism involving magnetic impurities such as ${\mathrm{Fe}}^{3+}$ present at the 10-100 at. ppm level. The vanadium ions are believed to be magnetically inert. It is concluded that the material under study is not antiferromagnetic at 4.2°K.